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<div class="titlepage"><div><div><h4 class="title">
<a name="geometry.reference.algorithms.num_segments"></a><a class="link" href="num_segments.html" title="num_segments">num_segments</a>
</h4></div></div></div>
<p>
          <a class="indexterm" name="idm45246433472544"></a>
Calculates the number of segments of a geometry.
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h0"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.description"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.description">Description</a>
        </h6>
<p>
          The free function num_segments calculates the number of segments of a geometry.
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h1"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.synopsis"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.synopsis">Synopsis</a>
        </h6>
<p>
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">&gt;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">num_segments</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">geometry</span><span class="special">)</span></pre>
<p>
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h2"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.parameters"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.parameters">Parameters</a>
        </h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                  <p>
                    Type
                  </p>
                </th>
<th>
                  <p>
                    Concept
                  </p>
                </th>
<th>
                  <p>
                    Name
                  </p>
                </th>
<th>
                  <p>
                    Description
                  </p>
                </th>
</tr></thead>
<tbody><tr>
<td>
                  <p>
                    Geometry const &amp;
                  </p>
                </td>
<td>
                  <p>
                    Any type fulfilling a Geometry Concept
                  </p>
                </td>
<td>
                  <p>
                    geometry
                  </p>
                </td>
<td>
                  <p>
                    A model of the specified concept
                  </p>
                </td>
</tr></tbody>
</table></div>
<h6>
<a name="geometry.reference.algorithms.num_segments.h3"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.returns"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.returns">Returns</a>
        </h6>
<p>
          The calculated number of segments
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h4"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.header"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.header">Header</a>
        </h6>
<p>
          Either
        </p>
<p>
          <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
        </p>
<p>
          Or
        </p>
<p>
          <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">algorithms</span><span class="special">/</span><span class="identifier">num_segments</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h5"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.conformance"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.conformance">Conformance</a>
        </h6>
<p>
          The function num_segments is not defined by OGC.
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h6"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.behavior"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.behavior">Behavior</a>
        </h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                  <p>
                    Case
                  </p>
                </th>
<th>
                  <p>
                    Behavior
                  </p>
                </th>
</tr></thead>
<tbody>
<tr>
<td>
                  <p>
                    pointlike (e.g. point)
                  </p>
                </td>
<td>
                  <p>
                    Returns 0
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
                    Segment
                  </p>
                </td>
<td>
                  <p>
                    Returns 1
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
                    Box
                  </p>
                </td>
<td>
                  <p>
                    Returns d * 2^(d-1), where d is the dimension of the box
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
                    Rangelike (linestring, ring)
                  </p>
                </td>
<td>
                  <p>
                    Returns boost::size(geometry) - 1
                  </p>
                </td>
</tr>
<tr>
<td>
                  <p>
                    Other geometries
                  </p>
                </td>
<td>
                  <p>
                    Returns the sum of the number of segments of its elements
                  </p>
                </td>
</tr>
</tbody>
</table></div>
<h6>
<a name="geometry.reference.algorithms.num_segments.h7"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.complexity"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.complexity">Complexity</a>
        </h6>
<p>
          Constant or Linear
        </p>
<h6>
<a name="geometry.reference.algorithms.num_segments.h8"></a>
          <span class="phrase"><a name="geometry.reference.algorithms.num_segments.examples"></a></span><a class="link" href="num_segments.html#geometry.reference.algorithms.num_segments.examples">Examples</a>
        </h6>
<p>
          Get the number of segments in a geometry
        </p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>

<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>


<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">multi_polygon</span>
        <span class="special">&lt;</span>
            <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">polygon</span>
                <span class="special">&lt;</span>
                    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;,</span> <span class="keyword">true</span><span class="special">,</span> <span class="keyword">false</span> <span class="comment">// cw, open polygon</span>
                <span class="special">&gt;</span>
        <span class="special">&gt;</span> <span class="identifier">mp</span><span class="special">;</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">read_wkt</span><span class="special">(</span><span class="string">"MULTIPOLYGON(((0 0,0 10,10 0),(1 1,8 1,1 8)),((10 10,10 20,20 10)))"</span><span class="special">,</span> <span class="identifier">mp</span><span class="special">);</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Number of segments: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">num_segments</span><span class="special">(</span><span class="identifier">mp</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
    <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
        </p>
<p>
          Output:
        </p>
<pre class="programlisting">Number of segments: 9
</pre>
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